noun
A device that turns liquid into a fine spray, often used for perfume, medicine, or cosmetics.
香水をアトマイザーに入れて持ち歩いている。
I carry perfume in an atomizer.
スプレー is a broader term for spray in general, including aerosol cans, while アトマイザー specifically refers to a device that atomizes liquid into a fine mist, often a small refillable container.
Borrowed from English 'atomizer'.