This study introduces the design and analysis of ultra-wideband band-stop filters based on a metal-insulator-metal (MIM) waveguide with triangle resonators. The optical features of the filters are determined numerically. Transmission values and field distributions have been obtained. To show the tunability of the resonances of the filters, parameter sweep analysis has been done. This feature provides the shifted wideband bandwidths from visible to mid-infrared regimes. The highest bandwidth is 859 nm for band-stop filtering in this work. Higher bandwidths can be achieved by increasing the number of resonators adjacent to the waveguide. This research offers the potential to improve the filtering capabilities of optical devices through the use of high-efficiency MIM waveguide-resonator systems.