Abstract: A tubular fluorescent lamp (2) comprises an electrode (8) mounted inside the glass tube (4) which is at least partly surrounded by an electrode cover (16) mounted inside the glass tube (4) and situated between the electrode (8) and the wall of the glass tube (4) at a distance from them. According to the invention, a spacer (24) is placed in such a way that when the electrode cover (16) unintentionally is moved from its mounting position in a radial direction relative to the longitudinal axis of the glass tube (4), contact occurs between the electrode cover (16) and the spacer (24), and between the spacer (24) and the inside of the wall of the glass tube (4), preventing the movement of the electrode cover (16) before it comes into direct contact with the inside of the wall of the glass tube (4). Thereby is prevented that the tubular fluorescent lamp cracks and may fall out from its fittings. The spacer is preferably a mica plate (24) with larger diameter than the electrode cover (16).