1. A bio-item searching apparatus that searches for a target bio-item with a keyword input by a user, comprising a control device, a storage device, and an output device, wherein the storage device includes: a bio-item literature set storage unit that stores a bio-item literature set having a literature in which the bio-item name is described for each of bio-items, and the control device includes: a number-of-literatures acquiring unit that searches each of the bio-item literature sets with the keyword to acquire the number (Nh) of literatures including the keyword for each of the bio-items; a candidate bio-item selecting unit that selects the bio-item in which the number-of-literatures Nh is 1 or larger as a candidate bio-item; a table creating unit that creates, for each of the candidate bio-items, a number-of-literatures table constituted by any one or both of a) the number-of-literatures Nh, and b) the number of literatures each not including the keyword and including the bio-item name (the number of literatures in the bio-item literature set of the bio-item—Nh); a correlation score calculating unit that calculates a correlation score between the bio-item and the keyword based on statistical calculation by using the number-of-literatures table for each of the candidate bio-items; and an output unit that outputs the candidate bio-items to the output device based on the correlation score calculated by the correlation score calculating unit.