The objective of the present invention is to provide a simple microorganism detection apparatus that reduces detection time and that provides improved detection sensitivity, especially for gram-negative bacteria. The microorganism detection apparatus of the present invention includes: a detection target introduction portion, into which a sample and reagents are to be introduced; a detector, for detecting the color tone of the reagent introduced into the detection target introduction portion; a sample holder, for holding the sample to be introduced into the detection target introduction portion; a culture solution holder, for holding a culture solution used for microorganism culturing; and reagent holders, for holding the reagents to be introduced into the detection target introduction portion, wherein the presence/absence of microorganisms in the sample is determined based on the detected color tone.