The invention provides an optical subcutaneous fat thickness measuring device capable of measuring the subcutaneous fat thickness at different parts of an organism even by means of simple operation of one input part and capable of enabling the device to be miniaturized with low cost. The optical subcutaneous fat thickness measuring device (10) comprises a light-emitting component (13), a first acceptance component (14) and a second acceptance component (15); a database part (17) memorizing functions shared in each part of the organism, wherein the functions cause the acceptance parameter value obtained according to the acceptance amount in an acceptance part to be related to the value of the subcutaneous fat thickness of each part of the organism; a control part (16) deducing the value ofthe subcutaneous fat thickness reference to the functions of the database part according to the acceptance parameter value; an input button (10b) indicating the control part (16) to begin to measure the subcutaneous fat thickness; and a display part (10a) reporting the value of the subcutaneous fat thickness deduced by the control part to a measured person.