An image pickup apparatus including an image sensor and display means configured to display a live view of images picked up by the image sensor, the image pickup apparatus comprising: detection means configured to perform a flicker detection operation to detect a flicker based on a plurality of images captured by the image sensor at predetermined intervals; control means configured to control the image sensor based on flicker information detected by the detection means, wherein the detection means is configured to perform first detection of the flicker detection operation in response to a user instruction which is different from an image pickup preparation instruction and an image pickup instruction whilst live view images are displayed on the display means, wherein the detection means is further configured to perform second detection of the flicker detection operation according to the image pickup preparation instruction or the image pickup instruction by a user, wherein, in a case that a flicker is detected in the first detection, the control means is configured to control driving of the image sensor so as to perform exposure for live view display on the display means after the first detection is performed in a charge accumulation period as an integer multiple of the light amount change period of the flicker detected in the first detection, wherein in a case that a flicker is detected in the second detection, the control means is configured to control driving of the image sensor so as to perform exposure for capturing a still image in accordance with a peak timing of a light amount change of the flicker detected in the second detection, and wherein the detection means is further configured to perform: the first detection and the second detection in a case that a first setting for performing a flickerless image capturing function is preset to ON; the first detection without performing the second detection in a case that the first setting is preset to OFF. detection means configured to perform a flicker detection operation to detect a flicker based on a plurality of images captured by the image sensor at predetermined intervals; control means configured to control the image sensor based on flicker information detected by the detection means, wherein the detection means is configured to perform first detection of the flicker detection operation in response to a user instruction which is different from an image pickup preparation instruction and an image pickup instruction whilst live view images are displayed on the display means, wherein the detection means is further configured to perform second detection of the flicker detection operation according to the image pickup preparation instruction or the image pickup instruction by a user, wherein, in a case that a flicker is detected in the first detection, the control means is configured to control driving of the image sensor so as to perform exposure for live view display on the display means after the first detection is performed in a charge accumulation period as an integer multiple of the light amount change period of the flicker detected in the first detection, wherein in a case that a flicker is detected in the second detection, the control means is configured to control driving of the image sensor so as to perform exposure for capturing a still image in accordance with a peak timing of a light amount change of the flicker detected in the second detection, and wherein the detection means is further configured to perform: the first detection and the second detection in a case that a first setting for performing a flickerless image capturing function is preset to ON; the first detection without performing the second detection in a case that the first setting is preset to OFF. the first detection and the second detection in a case that a first setting for performing a flickerless image capturing function is preset to ON; the first detection without performing the second detection in a case that the first setting is preset to OFF.