An electrical connector set includes a first substrate having a first conductor, and a first internal terminal having a first mounting portion and a second mounting portion that are mounted on the first conductor of the first substrate and a projecting portion extending in a curved shape between the first mounting portion and the second mounting portion. The electrical connector set further includes a second substrate having a second conductor, and a second internal terminal having a third mounting portion that is mounted on the second conductor of the second substrate and a recessed portion forming the third mounting portion at a bottom portion, in which the projecting portion of the first internal terminal and the recessed portion of the second internal terminal are configured to be fitted to each other.