A control valve includes a signal pressure passage that transmits a pilot pressure of first and second pilot chambers as a signal pressure of another device, a connecting groove that is formed in a spool and connects the first pilot chamber to the signal pressure passage when the spool is in a neutral position, a connecting hole that is formed in the spool and connects the second pilot chamber to the signal pressure passage, and a check valve that is interposed in the connecting hole and permits a flow only from the second pilot chamber to the signal pressure passage. The connecting groove connects the first pilot chamber to the signal pressure passage when the pilot pressure is led into the first pilot chamber, and blocks communication between the first pilot chamber and the signal pressure passage when the pilot pressure is led into the second pilot chamber.