A attachment and detachment apparatus removably attaches a filter container containing a filter, as a part of a filtration apparatus that filters fluid with the filter. The filter container includes a first mounting protrusion having a filter container flow path in fluid communication with the filter. An outer periphery surface of the first mounting protrusion includes at least two curved surfaces respectively formed to be at least a part of an arc surface. The attachment and detachment apparatus includes a first mounting protrusion holding part that holds the first mounting protrusion. The first mounting protrusion holding part having a holding part flow path for the fluid and a notch communicating between an area surrounded by the inner periphery surface and an outer side of the first mounting protrusion holding part.