Mold release film

The purpose of the present invention is to provide a mold release film which is suitable for the production of a flexible circuit board, and which is capable of suppressing the formation of wrinkles,while maintaining mold releasability. The present invention provides a mold release film which is suitable for the production of a flexible circuit board, and which has the front surface and the backsurface that have been subjected to surface roughening. The ten-point average roughness (Rz) of the front surface is from 4 [mu]m to 20 [mu]m (inclusive), and a mold release layer that constitutes theback surface has a thickness of 35 [mu]m or more (excluding the cases where the ten-point average roughness (Rz) of the front surface is from 4 [mu]m to 5 [mu]m (inclusive) and the mold release layerthat constitutes the back surface has a thickness of from 35 [mu]m to 36 [mu]m (inclusive)). 本发明的目的在于提供一种脱模膜，其适合于柔性电路基板的制造、且能够在保持脱模性的状态下抑制皱褶的产生。本发明为一种脱模膜，其适合于柔性电路基板的制造，所述脱模膜的表面和背面被粗面化，所述表面的十点平均粗糙度Rz为4μm以上且20μm以下，并且构成所述背面的脱模层的厚度