A microscope apparatus comprising: an immersion objective lens (113; 204; 301a, 301b) that condenses light from a sample through a liquid; a nozzle (125; 206; 303) that supplies the liquid to an upper surface of the immersion objective lens (113; 204; 301a, 301b); and a liquid feeding mechanism (115, 122-136, 202, 203) that cooperates with a lens moving mechanism (124, 130, 211, 302) that moves the immersion objective lens (113; 204; 301a, 301b) and optionally a sample moving mechanism (115; 202, 203) that holds and moves the sample, and moves the nozzle (125; 206; 303) relative to the immersion objective lens (113; 204; 301a, 301b) to supply the liquid, characterized in that: - the lens moving mechanism (124, 130) is a focusing mechanism that moves the immersion objective lens (113; 204; 301a, 301b) in a vertical direction to focus the immersion objective lens (113; 204; 301a, 301b) on the sample, the liquid feeding mechanism (115, 122-136, 202, 203) includes a nozzle moving mechanism (115, 122-136, 202, 203) that moves the nozzle (125; 206; 303) in conjunction with a vertical movement of the immersion objective lens (113; 204; 301a, 301b), and arranges and retracts the nozzle (125; 206; 303) with respect to the immersion objective lens (113; 204; 301a, 301b), or - the lens moving mechanism is a focusing unit that moves the immersion objective lens in a vertical direction to focus the immersion objective lens on the sample, the sample moving mechanism has a linear stage that moves the sample linearly in a direction perpendicular to the optical axis of the immersion objective lens, the nozzle is arranged on the linear stage so as to face with the immersion objective lens, and the liquid feeding mechanism (202, 203) moves the nozzle by the linear stage, and arranges and retracts the nozzle with respect to the immersion objective lens after the immersion objective lens has been lowered by said focusing unit and before the immersion objective lens is raised by the focusing unit, or - the microscope apparatus comprises a plurality of immersion objective lenses (301a, 301b), wherein the lens moving mechanism is an objective switching mechanism that holds the immersion objective lenses (301a, 301b) and moves the immersion objective lenses (301a, 301b) to selectively place the immersion objective lens (301a, 301b) under the sample, the nozzle is arranged on a moving path of the immersion objective lens (301a, 301b), and the liquid feeding mechanism (122-136, 202, 203) moves the immersion objective lens (301a, 301b) by the objective switching mechanism, and arranges and retracts the immersion objective lens (301a, 301b) with respect to the nozzle. an immersion objective lens (113; 204; 301a, 301b) that condenses light from a sample through a liquid; a nozzle (125; 206; 303) that supplies the liquid to an upper surface of the immersion objective lens (113; 204; 301a, 301b); and a liquid feeding mechanism (115, 122-136, 202, 203) that cooperates with a lens moving mechanism (124, 130, 211, 302) that moves the immersion objective lens (113; 204; 301a, 301b) and optionally a sample moving mechanism (115; 202, 203) that holds and moves the sample, and moves the nozzle (125; 206; 303) relative to the immersion objective lens (113; 204; 301a, 301b) to supply the liquid, - the lens moving mechanism (124, 130) is a focusing mechanism that moves the immersion objective lens (113; 204; 301a, 301b) in a vertical direction to focus the immersion objective lens (113; 204; 301a, 301b) on the sample, the liquid feeding mechanism (115, 122-136, 202, 203) includes a nozzle moving mechanism (115, 122-136, 202, 203) that moves the nozzle (125; 206; 303) in conjunction with a vertical movement of the immersion objective lens (113; 204; 301a, 301b), and arranges and retracts the nozzle (125; 206; 303) with respect to the immersion objective lens (113; 204; 301a, 301b), or - the lens moving mechanism is a focusing unit that moves the immersion objective lens in a vertical direction to focus the immersion objective lens on the sample, the sample moving mechanism has a linear stage that moves the sample linearly in a direction perpendicular to the optical axis of the immersion objective lens, the nozzle is arranged on the linear stage so as to face with the immersion objective lens, and the liquid feeding mechanism (202, 203) moves the nozzle by the linear stage, and arranges and retracts the nozzle with respect to the immersion objective lens after the immersion objective lens has been lowered by said focusing unit and before the immersion objective lens is raised by the focusing unit, or - the microscope apparatus comprises a plurality of immersion objective lenses (301a, 301b), wherein the lens moving mechanism is an objective switching mechanism that holds the immersion objective lenses (301a, 301b) and moves the immersion objective lenses (301a, 301b) to selectively place the immersion objective lens (301a, 301b) under the sample, the nozzle is arranged on a moving path of the immersion objective lens (301a, 301b), and the liquid feeding mechanism (122-136, 202, 203) moves the immersion objective lens (301a, 301b) by the objective switching mechanism, and arranges and retracts the immersion objective lens (301a, 301b) with respect to the nozzle.