An imaging apparatus to which any one of lens apparatuses including a first lens apparatus and a second lens apparatus is detachably mountable, the imaging apparatus comprising: a mount unit where a plurality of electric contacts (1001 - 1012) are arrayed, wherein the plurality of electric contacts (1001 - 1012) include: a first electric contact group (1006, 1007, 1008) used to perform first communication with a lens apparatus mounted to the imaging apparatus, and a second electric contact group (1009, 1010, 1011) used to perform communication that is different from the first communication with a lens apparatus mounted to the imaging apparatus, wherein the imaging apparatus is configured to perform communication using the first electric contact group (1006, 1007, 1008) with both of the first lens apparatus and the second lens apparatus, wherein the imaging apparatus is configured to perform communication using the second electric contact group with the second lens apparatus but is configured not to perform communication using the second electric contact group (1009, 1010, 1011) with the first lens apparatus, and wherein, where a direction of movement of the second lens apparatus with respect to the imaging apparatus when mounting the second lens apparatus to the imaging apparatus directly is a first direction, the second electric contact group (1009, 1010, 1011) and the first electric contact group (1006, 1007, 1008) are arrayed in the order of the second electric contact group (1009, 1010, 1011) and the first electric contact group (1006, 1007, 1008) in the first direction. a mount unit where a plurality of electric contacts (1001 - 1012) are arrayed, wherein the plurality of electric contacts (1001 - 1012) include: a first electric contact group (1006, 1007, 1008) used to perform first communication with a lens apparatus mounted to the imaging apparatus, and a second electric contact group (1009, 1010, 1011) used to perform communication that is different from the first communication with a lens apparatus mounted to the imaging apparatus, a first electric contact group (1006, 1007, 1008) used to perform first communication with a lens apparatus mounted to the imaging apparatus, and a second electric contact group (1009, 1010, 1011) used to perform communication that is different from the first communication with a lens apparatus mounted to the imaging apparatus, wherein the imaging apparatus is configured to perform communication using the first electric contact group (1006, 1007, 1008) with both of the first lens apparatus and the second lens apparatus, wherein the imaging apparatus is configured to perform communication using the second electric contact group with the second lens apparatus but is configured not to perform communication using the second electric contact group (1009, 1010, 1011) with the first lens apparatus, and wherein, where a direction of movement of the second lens apparatus with respect to the imaging apparatus when mounting the second lens apparatus to the imaging apparatus directly is a first direction, the second electric contact group (1009, 1010, 1011) and the first electric contact group (1006, 1007, 1008) are arrayed in the order of the second electric contact group (1009, 1010, 1011) and the first electric contact group (1006, 1007, 1008) in the first direction.