The present invention relates to a pet bath apparatus that provides an improved hinged door that provides a function designed to wash various kinds of pets, and more particularly to a bath tub (100) that improves the water washing function of a pet and a bath tub 15 is operated by expanding the seal 37 with compressed air to effectively block the leakage of the water. The first embodiment of the pet bath apparatus arrangement providing the improved hinged door is designed to wash various types of pets and includes a bath tub 100 and a hinged door (not shown) attached to the side 22 of the bath tub (100) is horizontally positioned in the form of a drum, one end of the front is opened, and a drainage hole (11) is provided at the bottom of the bathtub (100) A side portion of the hinged door 300 is fixed to a side portion 22 at a front side of the bath tub by a hinge 31 and a size of an outer portion is limited so as to be inserted into and detached from the inside 13 of the bath tub, A groove 33 is formed in the side face 32 of the door opening and the side walls A and B of the groove 33 are connected to each other along the outer periphery of the hinged door 300 and are parallel to each other, (33) to the front hose portion (35) A communicating inner duct 36 protrudes from the groove 33 and a seal 37 connected to the groove 33 is inserted to seal the periphery of the groove 33, The room 37 is inserted into the inside 13 of the bath tub by the compressed air supplied through the front hose 35 when the tub 37 is closed and is expanded toward the outside of the side end face 32 of the hatch door, Thereby providing a function of sealing and contacting the inside 13. As a second embodiment, in the first embodiment, the hinged door 300 is closed by being inserted into the inside 13 of the bath tub at one end, and the chamber 37 is expanded toward the outside of the side end face 32 of the hinged door, And washing the pet 14 with the bath water 15 filled in the bath tub 100
