A ranging device comprising: a driving unit that drives a light source to emit pulse light with respect to an object per frame term; a range image sensor that includes a plurality of range sensors (P 1 to P N) disposed in a one-dimensional direction, each of the plurality of range sensors (P 1 to P N) including: a charge-generating region generating charges in accordance with incidence of reflected light of the pulse light reflected off the object, first and second charge-accumulating regions accumulating the charge and disposed away from the charge-generating region to sandwich the charge-generating region in the one-dimensional direction, a first transfer-electrode disposed between the first charge-accumulating region and the charge-generating region, and a second transfer-electrode disposed between the second charge-accumulating region and the charge-generating region; a controlling unit (CONT) that outputs, per frame terms, in synchronism with emission of the pulse light, a first pulse-transfer-signal (S 1) to the first transfer-electrode in such a manner that the charges generated in the charge-generating region flows as signal charges in the first charge-accumulating region and a second pulse-transfer-signal (S 2) having a phase different from that of the first pulse-transfer-signal (S 1) to the second transfer-electrode in such a manner that the charges generated in the charge-generating region flows as the signal charges in the second charge-accumulating region; and an arithmetic unit that reads out, per frame terms, each of quantities of the signal charges accumulated in the first and second charge-accumulating regions and that arithmetizes a distance (d) to the object based on the readout quantities of charges, characterized in that the controlling unit (CONT) alternately switches orders in time series of the first pulse-transfer-signal (S 1) and the second pulse-transfer-signal (S 2) and outputs the first (S 1) and second (S 2) pulse-transfer-signals per frame terms, and the arithmetic unit arithmetizes the distance (d) to the object based on total quantities of the signal charges, in two frame terms consecutive in the time series, accumulated in the first charge-accumulating region and the second charge-accumulating region in accordance with the first (S 1) and second (S 2) pulse-transfer-signals having an identical phase. a driving unit that drives a light source to emit pulse light with respect to an object per frame term; a range image sensor that includes a plurality of range sensors (P 1 to P N) disposed in a one-dimensional direction, each of the plurality of range sensors (P 1 to P N) including: a charge-generating region generating charges in accordance with incidence of reflected light of the pulse light reflected off the object, first and second charge-accumulating regions accumulating the charge and disposed away from the charge-generating region to sandwich the charge-generating region in the one-dimensional direction, a first transfer-electrode disposed between the first charge-accumulating region and the charge-generating region, and a second transfer-electrode disposed between the second charge-accumulating region and the charge-generating region; a charge-generating region generating charges in accordance with incidence of reflected light of the pulse light reflected off the object, first and second charge-accumulating regions accumulating the charge and disposed away from the charge-generating region to sandwich the charge-generating region in the one-dimensional direction, a first transfer-electrode disposed between the first charge-accumulating region and the charge-generating region, and a second transfer-electrode disposed between the second charge-accumulating region and the charge-generating region; a controlling unit (CONT) that outputs, per frame terms, in synchronism with emission of the pulse light, a first pulse-transfer-signal (S 1) to the first transfer-electrode in such a manner that the charges generated in the charge-generating region flows as signal charges in the first charge-accumulating region and a second pulse-transfer-signal (S 2) having a phase different from that of the first pulse-transfer-signal (S 1) to the second transfer-electrode in such a manner that the charges generated in the charge-generating region flows as the signal charges in the second charge-accumulating region; and an arithmetic unit that reads out, per frame terms, each of quantities of the signal charges accumulated in the first and second charge-accumulating regions and that arithmetizes a distance (d) to the object based on the readout quantities of charges, characterized in that the controlling unit (CONT) alternately switches orders in time series of the first pulse-transfer-signal (S 1) and the second pulse-transfer-signal (S 2) and outputs the first (S 1) and second (S 2) pulse-transfer-signals per frame terms, and the arithmetic unit arithmetizes the distance (d) to the object based on total quantities of the signal charges, in two frame terms consecutive in the time series, accumulated in the first charge-accumulating region and the second charge-accumulating region in accordance with the first (S 1) and second (S 2) pulse-transfer-signals having an identical phase.