Please refer to FIG. 8A and FIG. 8B. FIG. 8A is a perspective view of an LED light bulb according to an embodiment of the present invention. FIG. 8B is a front view (or a side view) of an LED light bulb of FIG. 8A. The LED light bulb 20d shown in FIG. 8A and FIG. 8B is analogous to the LED light bulb 20c shown in FIG. 7A. As shown in FIG. 8A and FIG. 8B, the LED light bulb 20d comprises a lamp housing 12, a bulb base 16 connected to the lamp housing 12, two conductive supports 51a, 51b disposed in the lamp housing 12, supporting arms 15, a stem 19, and one single LED filament 100. The stem 19 comprises a stem bottom and a stem top opposite to each other. The stem bottom is connected to the bulb base 16. The stem top extends to inside of the lamp housing 12 (e.g., extending to the center of the lamp housing 12) along an elongated direction of the stem 19. For example, the stem top may be substantially located at a center of the inside of the lamp housing 12. In the embodiment, the stem 19 comprises the stand 19a. Herein the stand 19a is deemed as a part of the whole stem 19 and thus the top of the stem 19 is the same as the top of the stand 19a. The two conductive supports 51a, 51b are connected to the stem 19. The LED filament 100 comprises a filament body and two conductive electrodes 506. The two conductive electrodes 506 are at two opposite ends of the filament body. The filament body is the part of the LED filament 100 without the conductive electrodes 506. The two conductive electrodes 506 are respectively connected to the two conductive supports 51a, 51b. The filament body is around the stem 19. An end of the supporting arm 15 is connected to the stem 19 and another end of the supporting arm 15 is connected to the filament body.