PROBLEM TO BE SOLVED: To provide a washing device for a pet which enables an owner to wash a body of the pet easily while keeping posture of the pet constant and can be stored in a compact manner, and also to provide a washing device set for a pet provided with the same.SOLUTION: A washing device 1 for a pet is configured to wash a pet and includes a bathtub 10, posture retaining means 20, and a lid body 50. The bathtub 10 includes a bottom plate 12 and side plates 14 rising from peripheral edge portions of the bottom plate 12. The posture retaining means 20 is laid over the side plates 14 to be disposed above the bottom plate 12 and retains posture of the pet by supporting an abdominal part of the pet. The lid body 50 is detachably attached on the bathtub 10. The lid body 50 is provided on the bathtub 10 and includes a lid main body 55 having a seating surface 57 and leg parts 65 provided on the lid main body 55.
