The present invention prevents foreign matter from infiltrating into a control valve and enables reduction in the cost of the valve. A strainer is mounted on an attachment portion of a valve sleeve, and a valve spool is disposed in the sleeve so as to be free to slidably advance and retreat. The strainer includes engagement portions m1 contacting first contact sites ε1 and ε2 formed on the attachment portion and a contact portion contacting second contact sites ε3 and ε4 formed on the attachment portion. Since the strainer includes the engagement portions m1 in contact with the first contact sites ε1 and ε2 and the contact portion in contact with the second contact sites ε3 and ε4, the sleeve has sufficient sealing contact with the strainer 73 at the first and second contact sites ε1 to ε4.