Piezoelectric pump device having movable filter arrangement

A pump device comprising:

• a pump body including a first wall and a second wall, the first wall having a suction hole, the second wall having a discharge hole;
• a filter member located and shaped, on an outside of the pump body closer to the first wall, so as to overlap the suction hole when viewed in a direction orthogonal to the first wall;
• and
• at least one holding member holding the filter member at a distance from the pump body so that a distance between the first wall and at least a part of the filter member overlapping the suction hole is changeable,
• wherein the at least one holding member is shaped such that a space provided between the first wall and the part of the filter member overlapping the suction hole communicates with an outer edge of the filter member or an outside of the at least one holding member, without passage through the filter member in a state in which the part of the filter member overlapping the suction hole is apart from the first wall, and
• wherein the pump device is a piezoelectric pump.