An electrical junction box includes a circuit assembly including a circuit board and a conductive plate, a engaging component (terminal block), a frame including an installation portion to which the engaging component is installed. A first engaging portion (first bus bar) is formed on one end side of the circuit assembly, and a second engaging portion (second bus bar) is formed on another end side of the circuit assembly. The frame includes a first engaged portion (receiving portion) that is engaged with the first engaging portion and receives the one end side of the circuit assembly. The engaging component includes a second engaged portion (auxiliary receiving portion) that is engaged with the second engaging portion and receives the other end side of the circuit assembly.