A garment steamer includes a base body with a steam generator for generating steam, and a main body disposed at the upper side of the base body for moving the steam generated by the steam generator to the outside. A front press is hingedly fixed to the lower part of the main body to be attached to and detached from the front surface of the main body. A stretching means is disposed at opposite side surfaces of the main body to be unfolded outside the main body, and a pair of arm tensioners includes lower ends hingedly fixed to the front surface of the front press and upper ends configured to be turned and spaced apart from each other.