This heat generation quantity control apparatus is configured by being provided with: a heat flux sensor (10) that is disposed between first and second heat generating bodies, which are adjacent to each other; and a control unit (20) that controls heat generation quantities of the first and second heat generating bodies. The heat flux sensor (10) has a structure wherein: a plurality of first and second via holes that penetrate an insulating base material in the thickness direction are formed, said insulating base material being formed of a thermoplastic resin; first and second interlayer connecting members, which are formed of metals different from each other, are embedded in the first and second via holes; and the first and second interlayer connecting members are alternately connected in series. On the basis of sensor signals outputted from the heat flux sensor (10), the control unit (20) controls the heat generation quantities of the first and second heat generating bodies such that a heat flux between the first and second heat generating bodies is at a predetermined value or less.