To provide a multiple disc clutch in which the engagement/disengagement timing of the clutch can be adjusted to a fixed value, and an assembling method for the multiple disc clutch. Two kinds of clutch discs different at least in thickness are combined, and the clutch disc or discs are replaced with the clutch disc or discs of other thickness so that the total thickness of a required number of the combined clutch discs when a predetermined pressure is applied thereto will be equal to a predetermined size, whereby the total thickness is adjusted.