A　resist　(ma-N　2403　and　ZEP　520A7)-based　convenient　technology　to　fabricate　air　bridges　on　arbitrary　substrate　is　proposed.　It　involves　only　two　steps　of　electron-beam　lithography.　By　changing　the　exposure　dose　during　lithography,　the　resist　can　be　cross-linked　to　different　extent,　and　the　permanently　cross-linked　polymer　is　used　for　piers.　An　evaporated　205-nm-thick　Ti/Au　thin　film　is　used　to　construct　the　bridges.　Typically,　the　air　bridge　is　more　than　18　mu　m　long,　2　mu　m　high,　and　5　mu　m　wide.　Due　to　the　accumulated　strain　in　the　metal,　it　naturally　forms　an　arch　bridge,　rendering　no　need　for　critical　point　drying.　The　adhesion　between　the　metal　and　the　polymer　is　considerably　strong,　even　surviving　mild　sonication.　This　letter　should　contribute　to　a　facile　technology　for　manufacturing　air　bridges　for　various　applications　in　microelectromechanical　systems.　[2012-0101]