The invention relates to a portable containment device for manipulating organic and/or chemical substances, which includes: a transporting case including two half-cases (2, 3) connected by a hinged structure (4) such as to be movable between a closed position (F), in which the half-cases (2, 3) are against one another and define a stowing space for at least the hinged structure (4), and an open position (O), in which the half-cases (2, 3) are spaced apart from one another by being maintained vertical by the hinged structure (4) and in which the half-cases (2, 3) and the hinged structure (4) form a supporting structure for a flexible containment enclosure (20); and a plastic, removable and flexible containment enclosure (20) that is at least partially transparent, for forming a generally parallelepiped foldable isolation chamber provided with means (31, 32) for accessing the inside of the enclosure and with means (21) for attachment to the supporting structure. The containment enclosure (20) is collapsible inside the transporting case in the closed position (F). The invention also relates to a removable, flexible enclosure for such a device.