A module-type speech synthesizer was developed for rule-synthesis of Japanese, in order to find practical applications of rule-synthesis devices. The module can be built into any machine and can be used almost anywhere. Input to the module consists of katakana, accent marks, punctuation marks, and modification marks. The modification marks represent accent sandhi, between words on both sides. The size of the module is 66x46x15 mm and it weighs 59 grams. All necessary hardware and software components are included in the module. The electrical interface is compatible with common CPU buses. Syllable articulation is 63% comprehensible. It uses at most 160 mA from two 5V power supplies.