1. A component presence/absence judging apparatus for judging whether or not components are mounted at predetermined places on a board after component mounting operations which mount the components on the board, the apparatus comprising: an image pickup device for relatively moving the board and a camera to pickup images of the predetermined places on the board; ante-mounting feature acquisition means for acquiring at least brightness information as ante-mounting features from an ante-mounting image which the image pickup device picks up at each of the predetermined places on an ante-mounting board before mounting the components at the predetermined places thereon; post-mounting feature acquisition means for acquiring at least brightness information as post-mounting features from a post-mounting image which the image pickup device picks up at each of the predetermined places on a post-mounting board after mounting the components at the predetermined places thereon; classifier configuration means for configuring a classifier by registering the ante-mounting features and the post-mounting features and calculating a hyperplane in a support vector machine; post-mounting operation feature acquisition means for acquiring at least brightness information as post-mounting operation features from a post-mounting operation image which the image pickup device picks up at each of the predetermined places on an inspection board after mounting the components at the predetermined places thereon; input means for inputting the post-mounting operation features to the support vector machine configured as the classifier; and judgment means for judging whether or not a component is mounted at each of the predetermined places on the inspection board, by the support vector machine configured as the classifier, by judging which side of the hyperplane calculated in the support vector machine the post-mounting operation features belong to.