Microscope and observation method

A microscope, comprising:

• an illumination light emission portion that emits illumination light to a container containing a liquid and an observation target;
• a container support stage on which the container is placed and which supports the container;
• an objective lens on which the illumination light having passed through the container and the container support stage is incident;
• a focusing light emission portion that emits focusing light having a wavelength different from that of the illumination light from the container support stage side through the objective lens;
• a reflected light detection portion that detects reflected light, which is due to emission of the focusing light from the container support stage side, through the objective lens;
• a distance changing mechanism that changes a distance between the objective lens and the container support stage;
• and
• a processor configured to:
• perform autofocus control by controlling the distance changing mechanism based on the reflected light detected by the reflected light detection portion;
• and
• acquire focus control information including at least one of information of the container, information of an amount of the liquid, or information of a magnification of the objective lens,
• wherein the processor is further configured to change a method of the autofocus control based on the focus control information, and
• wherein the processor is further configured to acquire information of a culture period of the observation target as the information of the amount of the liquid.