A compressor comprising a compression mechanism and a drive mechanism which are disposed in a casing including a cylindrical member, the drive mechanism comprising: a stator fixed to an inner circumferential surface of the cylindrical member; and a rotor disposed inside the stator, the rotor being configured to rotate with a drive shaft, the compression mechanism comprising: a cylinder main body (21; 121) including a compression chamber in which a roller driven by the drive shaft is disposed; an end surface member (23; 123) attached to an end surface of the cylinder main body (21; 121); a muffler main body attached to the end surface members (23; 123); an intake hole provided in the cylinder main body (21; 121), the intake hole communicating with the compression chamber and extending in a direction crossing the drive shaft; and characterized by a circular hole (56; 156) provided in the cylinder main body or in the end surface member, the circular hole (56; 156) being located radially outside the compression chamber and extending in a direction parallel to the drive shaft, wherein: the circular hole (56; 156) opens, outside the muffler main body, to a space inside the casing; and at least a part of the circular hole (56; 156) is located within an area between two straight extension lines respectively extending in an axial direction of the intake hole from two line segments indicating a peripheral surface of the intake hole in a plan view obtained when viewing the cylinder main body (21; 121) and the end surface member (23; 123) in an axial direction of the drive shaft. a stator fixed to an inner circumferential surface of the cylindrical member; and a rotor disposed inside the stator, the rotor being configured to rotate with a drive shaft, the compression mechanism comprising: a cylinder main body (21; 121) including a compression chamber in which a roller driven by the drive shaft is disposed; an end surface member (23; 123) attached to an end surface of the cylinder main body (21; 121); a muffler main body attached to the end surface members (23; 123); an intake hole provided in the cylinder main body (21; 121), the intake hole communicating with the compression chamber and extending in a direction crossing the drive shaft; and characterized by a circular hole (56; 156) provided in the cylinder main body or in the end surface member, the circular hole (56; 156) being located radially outside the compression chamber and extending in a direction parallel to the drive shaft, wherein: the circular hole (56; 156) opens, outside the muffler main body, to a space inside the casing; and at least a part of the circular hole (56; 156) is located within an area between two straight extension lines respectively extending in an axial direction of the intake hole from two line segments indicating a peripheral surface of the intake hole in a plan view obtained when viewing the cylinder main body (21; 121) and the end surface member (23; 123) in an axial direction of the drive shaft. a cylinder main body (21; 121) including a compression chamber in which a roller driven by the drive shaft is disposed; an end surface member (23; 123) attached to an end surface of the cylinder main body (21; 121); a muffler main body attached to the end surface members (23; 123); an intake hole provided in the cylinder main body (21; 121), the intake hole communicating with the compression chamber and extending in a direction crossing the drive shaft; and characterized by a circular hole (56; 156) provided in the cylinder main body or in the end surface member, the circular hole (56; 156) being located radially outside the compression chamber and extending in a direction parallel to the drive shaft, wherein: the circular hole (56; 156) opens, outside the muffler main body, to a space inside the casing; and at least a part of the circular hole (56; 156) is located within an area between two straight extension lines respectively extending in an axial direction of the intake hole from two line segments indicating a peripheral surface of the intake hole in a plan view obtained when viewing the cylinder main body (21; 121) and the end surface member (23; 123) in an axial direction of the drive shaft. the circular hole (56; 156) opens, outside the muffler main body, to a space inside the casing; and at least a part of the circular hole (56; 156) is located within an area between two straight extension lines respectively extending in an axial direction of the intake hole from two line segments indicating a peripheral surface of the intake hole in a plan view obtained when viewing the cylinder main body (21; 121) and the end surface member (23; 123) in an axial direction of the drive shaft.