Generally, the hot embossing cycle time for fabricating microfeatures on the surface of polymer takes no < 10 min because the mold needs to be firstly heated to 10-40 degrees C above Tg and then cooled to temperature below Tg after certain time of holding pressing force. In this article, the Plate to Plate (P2P) Transition-Spanning Isothermal Hot Embossing method was proposed, specific of which was relatively short embossing cycle time of 15-60 s by setting and holding constant mold temperature in a narrow temperature interval around Tg in whole cycle of embossing substrate of PMMA. The experiment hot embossing device satisfied the needs of isothermal embossing process was designed and built up, on which the micro V-cut array with a pitch of 49 mm was successfully fabricated on the PMMA substrate. The experiments gave a confirmation of possibility for fabricating microfeatures by P2P Transition-Spanning Isothermal Hot Embossing method. (C) 2016 Society of Plastics Engineers