The present invention relates to a half body bathtub for a chair, and more particularly to a half body bathtub which includes a body part, a drawer part extracted from or inserted into one end of the body part to form a seating space； and a folding part disposed between the body party and the drawer part such that the half body bathtub may be usable as a chair if the drawer is inserted into the body part, so that a space utility of reducing an installation space of the half body bathtub and a usability of changing the purpose of the half body bathtub to a half body bathtub or a chair can be maximized. To achieve this, the present invention provides a half body bathtub having a heating part therein such that a user may enjoy a half body bathtub, which includes the following: a body part (100) including a first outer wall (110), one end of which is opened to form an edge with an entrance door (112) at one side thereof, a first bottom surface (120) formed on the bottom of the first outer wall (110), and a seating space (130) having a seating member (132) and a heating part (140) therein； an expansion part (200) which is extracted from or inserted into the body part (100) by a predetermined distance through the opened end of the body part (100) to maximize the utility of the installation space； and a folding part (300) provided between the body part (100) and the expansion part (200) such that a user may enjoy a half body bathtub by sealing the body part (100) and the expansion part (200) when the half body bathtub is used and the half body bathtub may be used as a chair if the expansion part (200) is inserted into the body part (100) when the half body bathtub is not used.본 발명은 의자 겸용 반신욕기에 관한 것으로서, 더욱 상세하게는, 본체부와 상기 본체부의 일단에서 일정길이 표출되거나 삽입되어 착석공간을 형성하도록 하는 서랍부 및 상기 본체부와 서랍부 사이에 구성되어 상기 서랍부를 본체부로 삽입시키면 의자로 사용 가능하도록 하는 절첩부로 구성함으로써, 반신욕기의 설치공간을 축소할 수 있는 공간활용성 및 반신욕기 또는 의자로 용도변경이 가능한 사용성을 극대화하는 데 그 목적이 있다.이를 위해 본 발명은, 내측에 히팅부가 구성되어 반신욕을 즐길 수 있도록 구성된 반신욕기에 있어서, 일단이 개방되고 테
