To prevent a substrate that is carried into a working position from catching up with the substrate to be carried out from the working position to range, while shortening a carrying tact by performing the carrying-out of the substrate from the working position and the carrying-in of the substrate to the working position in parallel.

When standard carrying-in time T1 is shorter than standard carrying-out time T2, only the start of carrying in the (n+1)th substrate 3b is delayed by a difference ΔT (=T2-T1+f) in carrying time. Thereby, before (n+1)th substrate 3b reaches a mounting position Pb, the nth substrate 3a passes through the carrying-out side sensor 24c, that is, the (n)th substrate 3a with components mounted is completely carried out from the mounting position Pb. At subsequent timing tn4, the (n+1)th substrate 3b is carried into the mounting position Pb. (f) is a positive value representing a predetermined time, and can be set at a fixed value on the basis of the configuration of the device, or can be a variable that can be changed according to production conditions.