Observation holder, observation apparatus, observation chip, and method of manufacturing observation chip

An observation holder including an accommodation unit having a rectangular shape in a planar view and configured to accommodate an observation target, and an observation unit formed below the accommodation unit, wherein

• the observation unit is configured such that the observation target accommodated in the accommodation unit can be observed from below,
• the accommodation unit includes:
• an accommodation main body in which a plurality of holes for accommodating the observation target are formed to be spaced apart from each other;
• and
• an accommodation upper portion formed on an upper portion of the accommodation main body,
• the accommodation upper portion includes:
• a wall surrounding a space above the accommodation main body, as a storage for storing a predetermined liquid;
• and
• an opening formed above the space, wherein
• the observation unit includes:
• a first plate covering the accommodation unit main body from below, the first plate having a plurality of through holes corresponding to the plurality of holes;
• and
• a translucent second plate covering the first plate from below,
• a cavity is formed in a lower surface of the first plate, the cavity connecting two adjacent through holes and having an outer edge surrounding the two adjacent through holes,
• the cavity and the second plate form a passageway connecting the two adjacent through holes, the passageway forming a connecting vessel.