To enjoy bathing while the body is completely relaxed by providing a means laid on a bath tub main body for supporting the inclined whole body of a bathing person in the state of drawing up his/her knees and supporting the arms horizontally on both sides.

A reclining type support unit 2 is laid in a bath tub main body 1, and the longitudinal sides are provided with fixing parts 21, 22 to be laid on the front and rear edges of the bath tub main body 1. A main part 25 is formed between both fixing parts 21, 22, and it has a structure as a whole such that a bathing person keeps his/her head at a high position near the front of the bath tub, the waist is located lower near the central area of the bath tub, and the body is supported in the state of drawing up his/her knees to confront the soles with the rear end of the bath tub. Accordingly, a bathing person draws his/her knees to be bent in the bath tub so that the waist is enough extended and the neck is lightly stretched to be fixed, whereby the body is completely relaxed to enjoy bathing.