Apparatus for and method of observing cells

Abstract

A cell observation apparatus includes an imaging device capable of imaging a vessel containing cells while varying a focal position, an illuminating device for irradiating the vessel with illuminating light; and a controller for controlling the imaging device. The controller includes: a z-stack imaging controller for causing the imaging device to take a plurality of z-stack images while varying the focal position; a variance value calculation part for calculating a variance value of pixels values for each of the z-stack images; an edge index value calculation part for calculating an edge index value indicative of edge strength for each of the z-stack images; a focus evaluation value calculation part for calculating a focus evaluation value having a minimum value in an in-focus position, based on the variance value and the edge index value; and an in-focus position estimation part for calculating the focal position where the focus evaluation value has a minimum value to estimate the in-focus position. This achieves the estimation of the in-focus position with high precision while suppressing the increase in the number of images taken for z-stack imaging.