PURPOSE: To obtain most suitable copies without requiring any skill by widening the effective adjusting range against proper exposures, by making exposures by changing both the quantity of light from the lamp to the photosensitive substance and the irradiating time.

CONSTITUTION: A change-over switch SW and a resistance R are added to a lamp lighting control circuit, and, when the change-over switch SW is connected to a contact point 10 when an exposure is to be made, the Ry is turned ON and the circuit is connected. When the circuit is connected, a voltage Vo is applied to the primary side of a transformer T and a 24V voltage is generated at the secondary side, and then a lamp 3 lights. Thus, the exposure is made. By using such circuit, most suitable copies can be obtained by changing the exposure by changing the exposing time. When it is arranged that the exposure illuminance can be changed in two steps in addition to the exposing time which can be changed operators can easily obtain most suitable copies even when a wide exposure adjusting range becmoes necessary.