This paper describes a method to detect particular speech segments as a keyword from speech database. The Generalized Hough Transform (GHT) has been used to find arbitrary complex shapes on the image plane. We extended the GHT to be able to deal with three-dimensional shapes and applied it to the keyword spotting in which a speech signal is represented as a spectral sequence. Based on experimental results on the keyword spotting in which 25 keywords were tried to extract from 750 utterances produced by 30 male speakers, we propose an approach for improving the keyword spotting performance. This approach combines GHT and a word spotting method based on DP matching.