A wheelchair, comprising: a seating bottom portion composed of a back bottom part, a seating bottom part (12b, 12c), and a leg bottom part which are bendable to each other; a chair bottom support member composed of a chair back bottom support member supporting the back bottom part and a chair leg bottom support member supporting the leg bottom part; a link member (13f, 13g) for actuating the chair leg bottom support member in conjunction with an action of the chair back bottom support member; a chair base portion coupled to the chair bottom support member; front wheels serving as freewheels provided in a front part of the chair base portion; wheel bottom support members whose intermediate parts are axially supported on a rear part of the chair base portion; rear wheels serving as freewheels provided in one ends of the wheel bottom support members; traveling wheels serving as fixed wheels provided in other ends of the wheel bottom support members; and wheel links coupling rear wheel sides of the wheel bottom support members and the chair back bottom support member, wherein in a case where the chair back bottom support member is lifted and the seating bottom portion is in a seating posture, lower surfaces of the traveling wheels are constantly positioned on a lower side of a plane composed of lower surfaces of the rear wheels and lower surfaces of the front wheels, and in a case where the chair back bottom support member is brought down and the sea ting bottom port ion is in a flat posture, the lower surfaces of the traveling wheels are constantly positioned on an upper side of the plane composed of the lower surfaces of the rear wheels and the lower surfaces of the front wheels. a seating bottom portion composed of a back bottom part, a seating bottom part (12b, 12c), and a leg bottom part which are bendable to each other; a chair bottom support member composed of a chair back bottom support member supporting the back bottom part and a chair leg bottom support member supporting the leg bottom part; a link member (13f, 13g) for actuating the chair leg bottom support member in conjunction with an action of the chair back bottom support member; a chair base portion coupled to the chair bottom support member; front wheels serving as freewheels provided in a front part of the chair base portion; wheel bottom support members whose intermediate parts are axially supported on a rear part of the chair base portion; rear wheels serving as freewheels provided in one ends of the wheel bottom support members; traveling wheels serving as fixed wheels provided in other ends of the wheel bottom support members; and wheel links coupling rear wheel sides of the wheel bottom support members and the chair back bottom support member, wherein in a case where the chair back bottom support member is lifted and the seating bottom portion is in a seating posture, lower surfaces of the traveling wheels are constantly positioned on a lower side of a plane composed of lower surfaces of the rear wheels and lower surfaces of the front wheels, and in a case where the chair back bottom support member is brought down and the sea ting bottom port ion is in a flat posture, the lower surfaces of the traveling wheels are constantly positioned on an upper side of the plane composed of the lower surfaces of the rear wheels and the lower surfaces of the front wheels.