Image forming apparatus

An image forming apparatus (1000) includes an image carrier(5 1); a facing member (56) facing the image carrier (51) via a transfer position (N); a power supply (200) to output a voltage between a first position (53a) on the image carrier (51) side and a second position (56a) on the facing member (56) side; a resistance detector (203) to detect electrical resistance between the first position (53a) and the second position (56a) via the transfer position (N); and a controller (300) to switch between a first transfer mode in which the power supply (200) outputs a direct current voltage, and a second transfer mode in which the power supply (200) outputs a superimposed voltage. When a toner image on the image carrier (51) is transferred onto a recording medium (P) at the transfer position (N), the controller (300) selects either the first transfer mode or the second transfer mode. When the resistance detector (203) detects the electrical resistance, the controller (300) selects the first transfer mode.