To provide a wiring substrate which can prevent short circuit between connection terminals, and which realizes reduction of the pitch between the connection terminals. The wiring substrate of the present invention includes a layered structure including one or more insulation layers and one or more conductor layers, and the wiring substrate is characterized in that a plurality of connection terminals are formed on the layered structure so as to be separated from one another; a filling member is filled between the connection terminals; and each of the connection terminals has a side surface composed of a contact surface which is in contact with the filling member, and a spaced surface which is not in contact with the filling member and which is located above the contact surface and below the top surface of the filling member.