An endoscope apparatus comprising: an insertion portion including a bendable bending portion (16, 16A) provided on a distal end side thereof; a bending drive section configured to electrically drive bending of the bending portion (16, 16A); an insertion shape detection section configured to detect an insertion shape of the distal end side of the insertion portion; and a bending control section configured to estimate a curve plane including the distal end side of the insertion portion in a state inserted in a curved tubular body cavity based on curve information of the distal end side of the insertion portion by the insertion shape detection section, and configured to perform control to drive bending of the bending portion (16, 16A) using information on the estimated curve plane, characterized in that the bending control section is configured to perform the control to drive bending of the bending portion (16, 16A) parallel to the curve plane, using the information on the curve plane, the endoscope apparatus further comprises an azimuth detection section configured to detect a predetermined bending direction, such as an upward direction, of the bending portion (16, 16A) in the curve plane as a reference azimuth around an axis of the distal end portion, the bending control section further being configured to set a virtual plane in the vicinity of a distal end of the insertion portion, with an axis direction of the insertion portion as a normal direction of the virtual plane, to calculate an intersection line between the virtual plane and the curve plane, and to calculate an angle (θ) formed by the intersection line and the reference azimuth, and the bending control section being configured to determine a direction of the angle (θ) to be a bending drive direction to drive bending of the bending portion (16, 16A) from a current bending position of the bending portion (16, 16A), and to perform control to drive bending of the bending portion (16, 16A in the direction of the angle (θ). an insertion portion including a bendable bending portion (16, 16A) provided on a distal end side thereof; a bending drive section configured to electrically drive bending of the bending portion (16, 16A); an insertion shape detection section configured to detect an insertion shape of the distal end side of the insertion portion; and a bending control section configured to estimate a curve plane including the distal end side of the insertion portion in a state inserted in a curved tubular body cavity based on curve information of the distal end side of the insertion portion by the insertion shape detection section, and configured to perform control to drive bending of the bending portion (16, 16A) using information on the estimated curve plane, characterized in that the bending control section is configured to perform the control to drive bending of the bending portion (16, 16A) parallel to the curve plane, using the information on the curve plane, the endoscope apparatus further comprises an azimuth detection section configured to detect a predetermined bending direction, such as an upward direction, of the bending portion (16, 16A) in the curve plane as a reference azimuth around an axis of the distal end portion, the bending control section further being configured to set a virtual plane in the vicinity of a distal end of the insertion portion, with an axis direction of the insertion portion as a normal direction of the virtual plane, to calculate an intersection line between the virtual plane and the curve plane, and to calculate an angle (θ) formed by the intersection line and the reference azimuth, and the bending control section being configured to determine a direction of the angle (θ) to be a bending drive direction to drive bending of the bending portion (16, 16A) from a current bending position of the bending portion (16, 16A), and to perform control to drive bending of the bending portion (16, 16A in the direction of the angle (θ).