To provide a chair type massage machine providing an appropriate massage by determining a seating posture of a user.

This chair type massage machine 1 is provided with a seat part 2 where the user can sit, a backrest part 4 provided in the rear part of the seat part 2, a medical treatment part 6 for treating a body part of the user and a control part 7 for controlling the operation of the medical treatment part, wherein the medical treatment part 6 has a contact detection sensor 70 provided vertically movable within a predetermined range in the height direction of the user and detecting a change in a contact degree of the body part of the user to the backrest part 4, and a seating posture determination means for determining the seating attitude of the user based on the contact detection at the predetermined position within the movable range of the medical treatment part 6.