A control apparatus for automatic transmission, comprising: an operating unit used to select a range of an automatic transmission including a traveling range and a non-traveling range; a detecting unit configured to detect the selected range by the operating unit; a valve disposed at an oil passage that couples a hydraulic pressure supply source and a plurality of forward movement friction elements (13, 14), a supply of a hydraulic pressure from the hydraulic pressure supply source to the plurality of forward movement friction elements (13, 14) being allowed while the traveling range is selected, the valve being configured to drive according to an operation of the operating unit; a hydraulic pressure controller (15, 16) disposed at the oil passage, the hydraulic pressure controller (15, 16) being configured to control the supplied hydraulic pressure to the plurality of forward movement friction elements (13, 14); and a control unit configured such that if the detecting unit detects the traveling range, the control unit controls the hydraulic pressure controller to supply the plurality of forward movement friction elements (13, 14) with the hydraulic pressure; characterized by a determining unit configured such that if the detecting unit detects the traveling range, the determining unit executes a determination, the determining unit being configured such that if operations of all the friction elements of the plurality of forward movement friction elements (13, 14) are not detected, the determining unit determining that an operation position of the operating unit is at an intermediate position between a position according to the traveling range and a position according to the non-traveling range, the determining unit being configured such that if the operation of a part of the friction elements among the plurality of forward movement friction elements (13, 14) is not detected, the determining unit determining that the hydraulic pressure controller (15, 16) has a failure. an operating unit used to select a range of an automatic transmission including a traveling range and a non-traveling range; a detecting unit configured to detect the selected range by the operating unit; a valve disposed at an oil passage that couples a hydraulic pressure supply source and a plurality of forward movement friction elements (13, 14), a supply of a hydraulic pressure from the hydraulic pressure supply source to the plurality of forward movement friction elements (13, 14) being allowed while the traveling range is selected, the valve being configured to drive according to an operation of the operating unit; a hydraulic pressure controller (15, 16) disposed at the oil passage, the hydraulic pressure controller (15, 16) being configured to control the supplied hydraulic pressure to the plurality of forward movement friction elements (13, 14); and a control unit configured such that if the detecting unit detects the traveling range, the control unit controls the hydraulic pressure controller to supply the plurality of forward movement friction elements (13, 14) with the hydraulic pressure; characterized by a determining unit configured such that if the detecting unit detects the traveling range, the determining unit executes a determination, the determining unit being configured such that if operations of all the friction elements of the plurality of forward movement friction elements (13, 14) are not detected, the determining unit determining that an operation position of the operating unit is at an intermediate position between a position according to the traveling range and a position according to the non-traveling range, the determining unit being configured such that if the operation of a part of the friction elements among the plurality of forward movement friction elements (13, 14) is not detected, the determining unit determining that the hydraulic pressure controller (15, 16) has a failure.