MILAN, Italy (AP) _ Giorgio Armani has done it again.

No matter how much you steel yourself against the charm of the designer and his staff, or shut your eyes to the sumptuous surroundings of his dowtown Milan palazzo, and blot out the beauty of past collections - it is to no avail. The clothes speak for themselves and confirm that Giorgio Armani is the leader of the Milan runway.

''Ravishing,'' exclaimed Kal Ruttenstein, fashion director at Bloomingdale's, after Wednesday night's show which took the fashion crowd by surprise with evening wear that excelled the daytime clothes, usually the Armani forte.

''Breathtaking'' sighed Elin Saltzman of Saks Fifth Avenue, as she kissed a satisfied Armani backstage.

But a comment by Janie Samet, fashion editor of the French daily Le Figaro, was worth a thousand adjectives. ''Il est le seul.'' (He is the only one), she pronounced, implying that only he in the school of Italian ready to wear could pose a threat to French fashion.

Usually Armani is a step ahead of the pack, showing the direction fashion will take the following season. He was the first to present androgynous women and one of the earliest to send short skirts and lingerie tops down the runway.

This season he preferred to flow with the tide, presenting a quiet, calm Spring-Summer 1989 collection, with delicate ethnic touches and a romantic maiden air, inspired by the avant-garde minimal designer Romeo Gigli.

It is the softness of the fabrics more than the cut of the clothes that give the collection its ethereal mood. Even Armani's daytime suits with his new jacket rounded at the shoulder and hem and curved gently at the waist, worn over a long slim skirt, or wide pants, are stitched in such airy tweeds they could float down the runway all on their own.

The blouse, always a strong point at Armani, becomes so light that at times it looks like a chiffon scarf tied around the midrift.

Fabrics are either checked or striped or printed in floral and geometric patterns. His evening wear is adorned in exquisite gold and silver embroidery and beading, reminiscent of Indian fabrics.

To emphasize the softness of his collection, Armani takes the edge out of the hemline, leaving it unevenly stitched and un-ironed, as if it had been tucked up in a hurry. This do-it-yourself look spells grim days ahead for seamstresses and private maids.

As the day goes on fabrics get lighter and sheerer. A series of cocktail suits were in Liberty and China porcelain prints with matching stockings. Then came the negligee gowns, or elongated slips in simple navy satin, worn over a chiffon, fringed shawl.

Embroidery started out slowly as piping on an otherwise simple gown or Tuxedo suit, to cover increasingly large areas of cloth until it became the entire dress.

Thus a youthful strapless gown was made up entirely of chiffon flowers bunched together to look like an Old English porcelain bouquet, and long skirts, pants and even shorts with matching tops were lavished with gold and silver threading and beaded craftsmanship. The latter was a throw-back to the ornate Indian embroidery popular in the 1960's as confirmed by the Indian evening bags which completed the look.

When they were not dazzling with jewels, his evening gowns were Ophelia -like in wispy chiffon, with a criss-cross bodice, and long skirt, with a dainty underskirt peering through.

Chiffon, in ombre pastel shades and creamy pinks was also used for pants and skirts alike to go with richly embroidered evening jackets.

To make sure the look remained innocent, Armani, the perfectionist, showed the flatest heels of the week. More slippers than shoes, closed in the front, but strapped at the back, they usually were made out of fabric.

Armani who tried the boudoir look several years ago, but didn't seem to like it, shied away from the bare-breasted nude look which has been the shock item on the runway this week - except for a single black chiffon gown in which white embroidered piping served a double purpose: it concealed bare breasts, while at the same time it framed a bare midrift right down to the navel.

The Armani price tag for the Spring-Summer 1989 is not outrageous, just expensive. A jeweled jacket costs approximately $3,000 to $3,500 depending on how elaborate is the embroidery, while an entirely embroidered outfit can run as high as $7,OOO. The dilemma is do you buy a new car, or do you dress Armani and walk.