A control valve (1, 201) for a variable displacement compressor for varying a discharging capacity of the variable displacement compressor by controlling a flow rate of refrigerant to be introduced from a discharge chamber to a crankcase of the compressor, the control valve (1, 201) comprising: a body having a discharge pressure chamber that can communicate with the discharge chamber, a crank pressure chamber that can communicate with the crankcase, a valve hole provided in a passage joining the discharge pressure chamber to the crank pressure chamber, and a guiding passage (28, 30) formed coaxially with the valve hole; an actuating rod (36, 236) slidably supported along the guiding passage (28, 30), the actuating rod (36, 236) having a valve element configured to open and close a valve section such that the valve element touches and leaves the valve hole; a solenoid configured to apply a solenoidal force in an opening or closing direction of the valve section to the valve element via the actuating rod (36, 236); and a seal section (110, 114; 212,214) provided between the actuating rod (36, 236) and the guiding passage (28, 30), the seal section (110, 114; 212,214) containing a sealing member (112, 116) therein where the sealing member (112, 116) serves to restrict leakage of the refrigerant from a high pressure side to a low pressure side, wherein the sealing member (112,116) is supported by either one of the body and the actuating rod (36;236) and is in contact with and slidable relative to the other one of the body and the actuating rod (36;236), wherein the seal section (110,114;212,214) is an annular recessed groove formed in either one of an inner surface of the guiding passage (28,30) into which the actuating rod (36;236) is inserted and an outer surface of the actuating rod (36;236) that is inserted into the guiding passage (28,30), the sealing member (112,116) being fitted in the recessed groove, characterised in that the actuating rod (36, 236) and the guiding passage (28, 30) are configured such that a clearance (CL1, CL3) between the actuating rod (36, 236) and the guiding passage (28, 30) which is at a higher-pressure side adjacent the annular recessed groove is larger than a clearance (CL2, CL4) therebetween which is at a lower-pressure side adjacent the recessed groove, and in that the clearance (CL2,CL4) at the lower-pressure side adjacent the annular recessed groove has such a size that the sealing member (112,216), when deformed due to a pressure difference between the higher-pressure side and the lower-pressure side is not stuck in the clearance (CL2,CL4) at the lower-pressure side. a body having a discharge pressure chamber that can communicate with the discharge chamber, a crank pressure chamber that can communicate with the crankcase, a valve hole provided in a passage joining the discharge pressure chamber to the crank pressure chamber, and a guiding passage (28, 30) formed coaxially with the valve hole; an actuating rod (36, 236) slidably supported along the guiding passage (28, 30), the actuating rod (36, 236) having a valve element configured to open and close a valve section such that the valve element touches and leaves the valve hole; a solenoid configured to apply a solenoidal force in an opening or closing direction of the valve section to the valve element via the actuating rod (36, 236); and a seal section (110, 114; 212,214) provided between the actuating rod (36, 236) and the guiding passage (28, 30), the seal section (110, 114; 212,214) containing a sealing member (112, 116) therein where the sealing member (112, 116) serves to restrict leakage of the refrigerant from a high pressure side to a low pressure side, wherein the sealing member (112,116) is supported by either one of the body and the actuating rod (36;236) and is in contact with and slidable relative to the other one of the body and the actuating rod (36;236), wherein the seal section (110,114;212,214) is an annular recessed groove formed in either one of an inner surface of the guiding passage (28,30) into which the actuating rod (36;236) is inserted and an outer surface of the actuating rod (36;236) that is inserted into the guiding passage (28,30), the sealing member (112,116) being fitted in the recessed groove, characterised in that the actuating rod (36, 236) and the guiding passage (28, 30) are configured such that a clearance (CL1, CL3) between the actuating rod (36, 236) and the guiding passage (28, 30) which is at a higher-pressure side adjacent the annular recessed groove is larger than a clearance (CL2, CL4) therebetween which is at a lower-pressure side adjacent the recessed groove, and in that the clearance (CL2,CL4) at the lower-pressure side adjacent the annular recessed groove has such a size that the sealing member (112,216), when deformed due to a pressure difference between the higher-pressure side and the lower-pressure side is not stuck in the clearance (CL2,CL4) at the lower-pressure side.