We have prepared an acrylic pressure sensitive adhesive bearing a mesogenic group (MesP) as a thermosensitive and heat resistance unit. MesP showed a "cool-off" function, where MesP loses its adhesion below the glass transition temperature and gives enough adhesion above that. Remarkably, peel modes of MesP at 250 degrees C and 20 degrees C after heating at 250 degrees C were adhesive failure, that means interfacial failure between the PSA and adherent, whereas those of an acrylic pressure sensitive adhesive bearing a long-alkyl side-chain group (C22P) were cohesive failure (CF) and a mixture of CF and stick-slip, respectively.