Disclosed herein is a mask-less exposure apparatus to enlarge or reduce an exposure area in a scan direction and a control method thereof. The mask-less exposure apparatus includes a light source unit configured to supply light, a spatial light modulation unit configured to selectively transmit the light to a substrate, a drive pulse generation unit configured to generate a drive pulse signal and adjust an operation beginning time of the spatial light modulation unit, a substrate shape measurement unit configured to measure a scan-direction length of the substrate, and a drive pulse correction unit configured to correct a drive pulse signal interval so as to enlarge or reduce an exposure area of the substrate according to the scan-direction length of the substrate.