A container capable of suppressing the unexpected opening of a pair of upper walls including a first side wall and a second side wall facing each other; a third side wall provided therebetween; a first upper wall and a second upper wall; and a locking member. The first side wall and the second side wall face each other. The first upper wall and the second upper wall are configured to be rotatable with respect to the first side wall and the second side wall, respectively. The locking member includes a fixed portion and an engagement portion, the fixed portion being fixed to the third side wall, the engagement portion being engaged with at least one of the first upper wall and the second upper wall to prevent the first upper wall and the second upper wall from opening.