Semiconductor substrate treatment method and treatment device

[Problem] To provide a technique by which it is possible to smooth a protective film when forming the protective film on a surface side (one side) before the step of reducing the thickness of a back surface side (the other side) of a semiconductor wafer on which an integrated circuit chip is formed. [Solution] Provided are: a module 51 that applies a curing agent 11 for peeling on a front surface side of a wafer W; a module 54 that cures the curing agent 11 via irradiation of ultraviolet rays; a module 52 that applies a curing agent 12 for a protective film on top of the curing agent 11; a module 56 that cures the curing agent 12 via irradiation of ultraviolet rays once the front surface of the curing agent has been pressed by a pressing member 14 comprising a glass plate; a device G that subsequently back grinds the wafer W; a module that bonds a dicing tape on the back surface side of the wafer W; and a module that subsequently irradiates laser light on the front surface side of the wafer W to alter the cur