A robot system comprising: a double arm robot having two robot arms (103L, 103R); each of the two robot arms (103L, 103R) being provided with a robot hand (120L, 120R); a rotation device which includes a rotation body capable of housing a work and a fixed part rotatably supporting the rotation body and which performs a predetermined process on the work; a contact unit provided on one of the robot hands (120L, 120R) for rotating the rotation body of the rotation device; a detection unit configured to detect a detection target part provided on the rotation body; a first control unit configured to control operation of at least one of the robot arms (103L, 103R) and at least one of the robot hands (120L, 120R) so that the contact unit rotates the rotation body up to a predetermined rotational position according to a result of detecting the detection target part by the detection unit; and a second control unit configured to control operation of the robot arms (103L, 103R) and the robot hands (120L, 120R) so that the work is installed at a predetermined work set part of the rotation body stopping at the predetermined rotational position or the work is removed from the work set part, wherein the rotation body of the rotation device is provided with a first insertion port, the contact unit is insertable into the first insertion port, and the first control unit is configured to control the operation of the robot arms (103L, 103R) and the robot hands (120L, 120R) so that the contact unit is inserted into the first insertion port, and is configured to set a rotational position of the rotation body at the predetermined rotational position at which the position of the work set part relative to the fixed unit becomes a predetermined particular position by controlling the operation of at least one of the robot arms (103L, 103R) and at least one of the robot hands (120L, 120R) to move the contact unit. a double arm robot having two robot arms (103L, 103R); each of the two robot arms (103L, 103R) being provided with a robot hand (120L, 120R); a rotation device which includes a rotation body capable of housing a work and a fixed part rotatably supporting the rotation body and which performs a predetermined process on the work; a contact unit provided on one of the robot hands (120L, 120R) for rotating the rotation body of the rotation device; a detection unit configured to detect a detection target part provided on the rotation body; a first control unit configured to control operation of at least one of the robot arms (103L, 103R) and at least one of the robot hands (120L, 120R) so that the contact unit rotates the rotation body up to a predetermined rotational position according to a result of detecting the detection target part by the detection unit; and a second control unit configured to control operation of the robot arms (103L, 103R) and the robot hands (120L, 120R) so that the work is installed at a predetermined work set part of the rotation body stopping at the predetermined rotational position or the work is removed from the work set part, wherein the rotation body of the rotation device is provided with a first insertion port, the contact unit is insertable into the first insertion port, and the first control unit is configured to control the operation of the robot arms (103L, 103R) and the robot hands (120L, 120R) so that the contact unit is inserted into the first insertion port, and is configured to set a rotational position of the rotation body at the predetermined rotational position at which the position of the work set part relative to the fixed unit becomes a predetermined particular position by controlling the operation of at least one of the robot arms (103L, 103R) and at least one of the robot hands (120L, 120R) to move the contact unit.