A storing section (70) stores a second initial contact instruction value, which is predefined as an instruction value for positioning a movable portion (5) to a second contact position where the movable portion (5) is contacted with a stopper (8), and an initial standby instruction value, which is predefined as an instruction value for positioning the movable portion (5) to a specified standby position within a moving range of the movable portion (5). A correcting section (42) calculates an actual standby instruction value by correcting the initial standby instruction value, based on a second actual contact instruction value obtained when a contact detection section (41) has detected that the movable portion (5) is positioned to the second contact position, and the second initial contact instruction value. A setting section (43) sets a standby position corresponding to the actual standby instruction value, as an actual standby position of the movable portion (5).