PROBLEM TO BE SOLVED: To provide an endoscope apparatus capable of alleviating the swinging of images observed through an optical system including a movable lens.SOLUTION: An endoscope apparatus 1 comprises: an image pickup device 23 an imaging optical system including at least one movable lens 21 which is movable along an optical axis J1 a shaft member 11 having a cam part 30 which is rotatable about a rotation axis J2 parallel with the optical axis J1, and which extends circumferentially about the rotation axis J2 a drive part 13 rotationally driving the shaft member 11 a movable lens holding member 14 which has a follower 15 contacting the cam part 30 in a direction along the rotation axis J2 and sliding on the cam part 30, and which is movable along the shaft member 11 and an energization member 16 for energizing the follower 15 in a direction along the rotation axis J2 and toward the cam part 30. The cam part 30 includes two cam surfaces 30b, 30c circumferentially connecting with each other and being circumferentially sloped differently from each other, and has a curved surface 15c provided on a circumference of the contact part 15a which is in contact with a cum surface of the follower 15.SELECTED DRAWING: Figure 2
