C5F10O　has　the　potential　to　replace　SF6　as　an　insulation　gas　in　switchgears　due　to　its　high　breakdown　field　strength　and　low　global　warming　potential.　However,　as　a　newly　synthesized　gas,　the　chemical　characteristics　of　C5F10O　are　not　well　known.　In　particular,　the　discharge　products　of　C5F10O　are　not　clear,　which　limits　its　insulating　capability　evaluation　in　long-term　use,　and　further　hinders　the　development　of　a　gas　sensor　to　monitor　the　insulation　deterioration　of　C5F10O-containing　switchgears.　In　this　paper,　electron　attachment　mass　spectrometry　(MS)　was　proposed　to　detect　the　decomposed　products　of　C5F10O　under　pulsed　spark　discharge　condition.　It　was　found　that　the　ionization　source　of　the　MS　had　an　optimal　electron　energy　of　2　eV　to　avoid　decomposing　the　gas　molecules　to　be　detected　while　having　a　high　detection　sensitivity.　The　detected　discharge　products　mainly　included　CF4,　C2F4,　C3F6,　C3HF5,　C3F8,　C3HF7,　C4F10,　C5F10,　C6F12,　C3F4O　and　C2F6O,　while　CF4,　C3HF5,　C3HF7,　C5F10,　C6F12,　C3F4O　and　C2F6O　were　not　detected　using　GCMS.　Based　on　the　nonionization　measurement,　the　decomposition　mechanism　was　deduced.　Also,　it　was　found　that　the　densities　of　some　products,　such　as　C3F6,　C3F8,　C4F10　were　increasing　with　the　discharge　voltage　and　the　number　of　discharge　pulses,　implying　that　these　species　might　be　used　as　indicators　for　the　discharge　accumulation　effects　such　as　the　insulation　deterioration　of　switchgears.　©　2020　IOP　Publishing　Ltd.