A laminated substrate includes: a first substrate; a second substrate having a through-hole; a third substrate; a first adhesive layer bonding a rear surface of the first substrate and a front surface of the second substrate; a second adhesive layer bonding a rear surface of the second substrate and a front surface of the third substrate; a first post penetrating through the first adhesive layer, electrically connecting the first substrate to the second substrate, and made of an alloy of a high melting point metal and a low melting point metal; a second post penetrating through the second adhesive layer, electrically connecting the second substrate to the third substrate, and made of an alloy of the high melting point metal and the low melting point metal; and an electronic component fixed to the front surface of the third substrate and disposed in the through-hole of the second substrate.