The disclosure provides a volatile liquid heater which is used with a volatile liquid bottle. The volatile liquid heater includes a main body, a heater circuit board, a heating element and an absorption element. One side of the main body defines an opening. The other side opposite to the one side of the main body defines at least one hole. There is a chamber in the main body. The chamber is connected to the opening and the hole. The outside of the main body has two bevel angles which are adjacently disposed to the opening. The heater circuit board is connected to the main body. The heating element is disposed in the chamber and is coupled to the heater circuit board. The absorption element is detachably disposed in the chamber and is connected to the heating element. When the volatile liquid bottle pierces through the opening to dispose in the chamber, the absorption element pierces through and is disposed in the volatile liquid bottle, and the bottle mouth of the volatile liquid bottle is toward the hole. The disclosure also provides an anti-mite device which has the volatile liquid heater.本新型揭露一種揮發液加熱器,與揮發液瓶配合使用。揮發液加熱器包括本體、加熱器電路板、加熱件及吸附件。本體的一側界定有開口,本體相對於該側的另一側界定有至少一開孔,本體內具有腔室,與開口及開孔連通,本體外更具有二斜角,鄰近開口設置。加熱器電路板與本體連接。加熱件設置於腔室內並與加熱器電路板耦接。吸附件可分離地設置於腔室內並與加熱件連接,當揮發液瓶穿過開口以設置於腔室內時,吸附件穿設於揮發液瓶內,且揮發液瓶的瓶口朝向開孔。本新型另揭露一種具有揮發液加熱器的防螨裝置。