Abstract: A combinative electronic circuit element composed of a cube-shaped block having an electronic component assembled therein. The block contains a pair of recesses formed in one pair of its outer opposite surfaces and a pair of projections on another pair of outer opposite surfaces, hence a total of four block-engaging surfaces or four joints. To the bottom surface of each recess and to the top surface of each projection is fixed a contact plate, which is then connected to said electronic component within said block so that upon engagement of a recess of one block with a projection of another block, the two electronic components housed in the two blocks are in communication with each other. A plurality of blocks each containing a different electronic component can be put together according to a given electronic circuit diagram by bringing said recess and projection into union so as to form a complete electronic circuit.