Provided is an electronic control device including a first electronic component having a first heat generation amount, a second electronic component having a second heat generation amount smaller than the first heat generation amount, a substrate on which the first and second electronic components are mounted, and a housing that accommodates the first electronic component, the second electronic component and the substrate, and includes a case for heat radiation having a heat radiation structure through which heat of the first and second electronic components is radiated. The heat radiation structure includes a heat radiation block that is heat-bonded to the first electronic component, and a plurality of plate-shaped heat radiation fins extending outward from an outer peripheral portion of the heat radiation block.