The text search apparatus has an information storage that stores plural transposed indexes associating characters or character strings appearing in a document to be searched with the appearance positions of the characters or character strings. The transposed indexes were generated for a document in which beginning marks are added in front of texts to be subject to forward matching search. The incremental searcher of the text search apparatus adds a beginning mark in front of a search keyword and executes a forward matching search using a set of transposed indexes. The main searcher executes a partial match search using the same set of transposed indexes.