A shop where hairdressing, styling, and other beauty treatments are provided. Often used interchangeably with 美容院, though 美容室 can sound slightly more formal or refer to a room within a larger facility.
A new beauty salon opened in front of the station.
I had my hair cut at the beauty salon.
Compound of 美容 (beauty) and 室 (room). The word follows standard Sino-Japanese word formation.