A heat flow distribution measurement device comprising: a sensor module (2, 200, 201, 202) including one multilayer substrate and a plurality of heat flow sensor portions, the multilayer substrate having one surface (2a, 200a) and another surface (2b, 200b) opposite to the one surface and having a plurality of stacked insulating layers (100,110, 120), the plurality of heat flow sensor portions being arranged inside of the multilayer substrate, and an arithmetic portion that arithmetically determines the heat flow distribution on the basis of the output produced by each of the plurality of heat flow sensor portions; wherein each of the plurality of heat flow sensor portions is provided by an electrically independent thermoelectric conversion element and, when the sensor module is placed with the one surface facing a measurement target of which a heat flow distribution is to be measured, each of the thermoelectric conversion elements produces an electric output in accordance with a heat flow passing through the inside of the multilayer substrate in a direction extending from one of the one surface and the another surface to the other of the one surface and the another surface, and wherein, in a direction along the one surface, the plurality of heat flow sensor portions are aligned in one row or a plurality of rows in one direction, the heat flow distribution measurement device further comprising: a movement unit that moves the sensor module in a direction intersecting the one direction, wherein the arithmetic portion arithmetically determines the heat flow distribution on the basis of the output produced by each of the plurality of heat flow sensor portions when the sensor module is moved and a position of the sensor module when the output is produced. a sensor module (2, 200, 201, 202) including one multilayer substrate and a plurality of heat flow sensor portions, the multilayer substrate having one surface (2a, 200a) and another surface (2b, 200b) opposite to the one surface and having a plurality of stacked insulating layers (100,110, 120), the plurality of heat flow sensor portions being arranged inside of the multilayer substrate, and an arithmetic portion that arithmetically determines the heat flow distribution on the basis of the output produced by each of the plurality of heat flow sensor portions; wherein each of the plurality of heat flow sensor portions is provided by an electrically independent thermoelectric conversion element and, when the sensor module is placed with the one surface facing a measurement target of which a heat flow distribution is to be measured, each of the thermoelectric conversion elements produces an electric output in accordance with a heat flow passing through the inside of the multilayer substrate in a direction extending from one of the one surface and the another surface to the other of the one surface and the another surface, and wherein, in a direction along the one surface, the plurality of heat flow sensor portions are aligned in one row or a plurality of rows in one direction, the heat flow distribution measurement device further comprising: a movement unit that moves the sensor module in a direction intersecting the one direction, wherein the arithmetic portion arithmetically determines the heat flow distribution on the basis of the output produced by each of the plurality of heat flow sensor portions when the sensor module is moved and a position of the sensor module when the output is produced. a movement unit that moves the sensor module in a direction intersecting the one direction, wherein the arithmetic portion arithmetically determines the heat flow distribution on the basis of the output produced by each of the plurality of heat flow sensor portions when the sensor module is moved and a position of the sensor module when the output is produced.