Provided is a tube joining apparatus that allows a user to easily and properly set tubes to be joined, and can prevent occurrence of joining failures due to tube setting errors.A tube joining apparatus 1 includes a housing 10, a lid 22 relatively movable toward and away from the housing, a tube holding part 23 that holds a first tube T1 and a second tube T2 individually in a state of being placed side by side in an oblique direction D1 with respect to a height direction Z of the housing, and a tube pressing part 25 that presses the first tube and the second tube against each other as the lid relatively moves toward the housing.