Infusion set for administering a medicament delivered by an infusion pump which can be carried separately from the infusion set, a) the infusion set comprising a disposable part, a reusable part, and an electrically powered functional component (7, 8), b) the disposable part comprising: b1) an adhesive underside for attachment at an infusion site on a person's skin, b2) a single lumen infusion cannula which projects from the underside and is the only skin piercing or penetrating element of the infusion set, b3) a first connector for fluidically connecting the cannula to the infusion pump, b4) and a second connector, c) and the reusable part comprising: c1) an energy source for electrically powering the functional component (7, 8), c2) and a third connector mating with the second connector of the disposable part to interconnect the disposable part and the reusable part, d) wherein the reusable part is in the interconnected state fluidically isolated from the disposable part; e) wherein the disposable part comprises a feeding line fluidically connecting an upstream end of the first connector with a downstream end of the cannula to feed and deliver the medicament via the disposable part and bypass the reusable part; characterized in that f) the disposable part comprises a primary base member and a secondary base member which are formed separately and jointly fixed one to the other such as to jointly form a chamber suitable for disposing an air degasser in the medicament flow; and g) wherein: g1) the primary base member comprises the single lumen infusion cannula and the second connector; and g2) the secondary base member comprises the first connector. a) the infusion set comprising a disposable part, a reusable part, and an electrically powered functional component (7, 8), b) the disposable part comprising: b1) an adhesive underside for attachment at an infusion site on a person's skin, b2) a single lumen infusion cannula which projects from the underside and is the only skin piercing or penetrating element of the infusion set, b3) a first connector for fluidically connecting the cannula to the infusion pump, b4) and a second connector, b1) an adhesive underside for attachment at an infusion site on a person's skin, b2) a single lumen infusion cannula which projects from the underside and is the only skin piercing or penetrating element of the infusion set, b3) a first connector for fluidically connecting the cannula to the infusion pump, b4) and a second connector, c) and the reusable part comprising: c1) an energy source for electrically powering the functional component (7, 8), c2) and a third connector mating with the second connector of the disposable part to interconnect the disposable part and the reusable part, c1) an energy source for electrically powering the functional component (7, 8), c2) and a third connector mating with the second connector of the disposable part to interconnect the disposable part and the reusable part, d) wherein the reusable part is in the interconnected state fluidically isolated from the disposable part; e) wherein the disposable part comprises a feeding line fluidically connecting an upstream end of the first connector with a downstream end of the cannula to feed and deliver the medicament via the disposable part and bypass the reusable part; characterized in that f) the disposable part comprises a primary base member and a secondary base member which are formed separately and jointly fixed one to the other such as to jointly form a chamber suitable for disposing an air degasser in the medicament flow; and g) wherein: g1) the primary base member comprises the single lumen infusion cannula and the second connector; and g2) the secondary base member comprises the first connector. g1) the primary base member comprises the single lumen infusion cannula and the second connector; and g2) the secondary base member comprises the first connector.