A control apparatus for an automatic transmission mechanism including: an oil pressure pump that is driven by a drive source for driving a vehicle, for pressurizing hydraulic oil; a transmission that has a drive pulley, a driven pulley, and a belt wound around the drive pulley and the driven pulley; first oil pressure-supplying means for regulating an oil pressure generated by the oil pressure pump to a first command oil pressure (PDRCMD), and supplying the oil pressure to a cylinder chamber of the drive pulley via a first oil passage (72, 72a, 73); and second oil pressure-supplying means for regulating the oil pressure generated by the oil pressure pump to a second command oil pressure (PDNCMD), and supplying the oil pressure to a cylinder chamber of the driven pulley via a second oil passage (72, 72b, 74), the control apparatus comprising: drive source start-detecting means for detecting beginning of a start of the drive source; first command oil pressure-setting means for setting the first command oil pressure (PDRCMD) to a first predetermined oil pressure substantially equal to 0 when the beginning of the start of the drive source has been detected; the control apparatus being characterized by further comprising: driven oil pressure-detecting means for detecting an oil pressure supplied to the driven pulley; second command oil pressure-setting means for setting the second command oil pressure (PDNCMD) to a second predetermined oil pressure higher than the first predetermined oil pressure when the beginning of the start of the drive source has been detected; and filling completion-determining means for determining completion of filling of the cylinder chamber of the driven pulley with the hydraulic oil, when the oil pressure detected by said driven oil pressure-detecting means has reached a predetermined threshold value (PDNTH), wherein said first command oil pressure-setting means starts to increase the first command oil pressure (PDRCMD) at a time when the completion of the filling of the cylinder chamber of the driven pulley has been determined after the beginning of the start of the drive source is detected by said drive source start-detecting means. an oil pressure pump that is driven by a drive source for driving a vehicle, for pressurizing hydraulic oil; a transmission that has a drive pulley, a driven pulley, and a belt wound around the drive pulley and the driven pulley; first oil pressure-supplying means for regulating an oil pressure generated by the oil pressure pump to a first command oil pressure (PDRCMD), and supplying the oil pressure to a cylinder chamber of the drive pulley via a first oil passage (72, 72a, 73); and second oil pressure-supplying means for regulating the oil pressure generated by the oil pressure pump to a second command oil pressure (PDNCMD), and supplying the oil pressure to a cylinder chamber of the driven pulley via a second oil passage (72, 72b, 74), the control apparatus comprising: drive source start-detecting means for detecting beginning of a start of the drive source; first command oil pressure-setting means for setting the first command oil pressure (PDRCMD) to a first predetermined oil pressure substantially equal to 0 when the beginning of the start of the drive source has been detected; drive source start-detecting means for detecting beginning of a start of the drive source; first command oil pressure-setting means for setting the first command oil pressure (PDRCMD) to a first predetermined oil pressure substantially equal to 0 when the beginning of the start of the drive source has been detected; the control apparatus being characterized by further comprising: driven oil pressure-detecting means for detecting an oil pressure supplied to the driven pulley; second command oil pressure-setting means for setting the second command oil pressure (PDNCMD) to a second predetermined oil pressure higher than the first predetermined oil pressure when the beginning of the start of the drive source has been detected; and filling completion-determining means for determining completion of filling of the cylinder chamber of the driven pulley with the hydraulic oil, when the oil pressure detected by said driven oil pressure-detecting means has reached a predetermined threshold value (PDNTH), wherein said first command oil pressure-setting means starts to increase the first command oil pressure (PDRCMD) at a time when the completion of the filling of the cylinder chamber of the driven pulley has been determined after the beginning of the start of the drive source is detected by said drive source start-detecting means. driven oil pressure-detecting means for detecting an oil pressure supplied to the driven pulley; second command oil pressure-setting means for setting the second command oil pressure (PDNCMD) to a second predetermined oil pressure higher than the first predetermined oil pressure when the beginning of the start of the drive source has been detected; and filling completion-determining means for determining completion of filling of the cylinder chamber of the driven pulley with the hydraulic oil, when the oil pressure detected by said driven oil pressure-detecting means has reached a predetermined threshold value (PDNTH), wherein said first command oil pressure-setting means starts to increase the first command oil pressure (PDRCMD) at a time when the completion of the filling of the cylinder chamber of the driven pulley has been determined after the beginning of the start of the drive source is detected by said drive source start-detecting means.