To provide a pulse emission controller in which the failure of an image pickup means due to pulse emission can not be generated, and a load on a pulse light source can be reduced.

This pulse emission controller S2 includes a pulse light source 11, image pickup means 12, and reading control circuit. The pulse light source 11 emits a pulse light P1 to at least one of a photosensitive substrate 7 or a mask 4 on which a transfer pattern is formed as an objective site in an almost constant period. The image pickup means 12 reads an image signal SG1 obtained by receiving a reflected light or a transmitted light from the objective site. The reading control circuit controls the reading of the image pickup means 12 by starting the reading of the image signal SG1 of the image pickup means 12 after the end of the emission of the pulse light source 11, and ending the reading of the image signal SG1 before the next emission of the pulse light source 11.