PURPOSE: To improve accuracy of relative position detection between an original film and an exposure substrate and to further improve lamination accuracy during exposure by detecting relative position relation between a relation for a misregistration detection value.

CONSTITUTION: A laser diode and a line sensor are built in a collimator 223. Optical axis 222 is projected to a reflection mirror 221 attached to a body tube wall of a pick-up 12 approximately vertical from a laser diode. When an angle of the reflection mirror 221 changes to the collimator 223, a position of a projection spot returning from the reflection mirror 221 changes on a line sensor, and it is thereby detected. Position control of each pick-up based on a value thereof is carried out. Thereby, it is possible to improve accuracy of relative position detection between an original film and an exposure substrate and to improve aligning accuracy during exposure.