We present a design of the broad band telescope with the angular resolution booster. A concept of the Xray imaging system with high angular-resolution and moderate sensitivity was presented by Maeda et al. (submitted). In the concept, a two-dimensional detector, i.e., imager, is put at a slightly defocused position of the focusing mirror, rather than right at the mirror focus as in the standard optics. The detector at the off-focus captures the microcosm of front mask-slits that are placed on the front of the mirror. The masks work as a modulation collimator and boost the angular resolution of the focusing telescope. The major advantage of this concept is that a much better angular resolution by an order of 2-3 or more than in the conventional optics is achievable, while a high throughput (large effective area) is maintained. We therefore present an example of a booster for a broad-band telescope. Using the technique of the Pt/C depth-graded supermirror, the broadband coverage up to 80 keV is discussed.