To obtain a directional control valve superior in workability and maintenanceability by mounting a pilot valve, a printed circuit board and the like on a top surface of a main valve section efficiently so that easy disassembly and assembly are achieved. A valve adapter is mounted on a top surface of a housing of a main valve section with first screws, pilot valves are mounted on the valve adapter with second screws, a printed circuit board is disposed above the pilot valves, and is electrically connected thereto, a protective cover for covering the valve adapter, the pilot valves, and the printed circuit board is mounted airtightly to the top surface of the housing with third screws, a pilot supply flow channel is formed between the valve adapter and the housing, and relay holes for bringing the pilot valves into communication with pilot flow channel ports are provided on the valve adapter.