To provide inspection devices, transplantation devices, inspection methods, and computer programs, which perform an inspection for screening a seedling by a simple method.SOLUTION: Provided is an inspection device comprising: a specifying unit that specifies a circumcircle of a contour of a leaf portion of a seedling in a captured image; a calculating unit that calculates an index value based on the size of the circumscribed circle specified by the specifying unit; and a determination unit that determines whether the seedling is good/bad based on the index value calculated by the calculation unit, in an inspection device that inspects the state of the seedling based on an image obtained by imaging the seedling of the plant P.SELECTED DRAWING: Figure 4【課題】簡易な方法で苗選別のための検査を行なう検査装置、移植装置、検査方法及びコンピュータプログラムを提供する。【解決手段】植物Pの苗を撮像した撮像画像に基づいて苗の状態を検査する検査装置において、撮像画像における苗の葉の部分の輪郭の外接円を特定する特定部と、特定部により特定された外接円のサイズに基づき指標値を算出する算出部と、算出部によって算出した指標値に基づき、苗の良/不良を判定する判定部とを備える検査装置。【選択図】図4