A heat-resistant material comprising a Rh-based alloy, wherein the Rh-based alloy is a highly heat-resistant and high strength alloy comprising a Rh-based alloy where Al and W as essential additive elements are added to Rh; the Rh alloy comprises 0.2 to 15.0 mass% of Al and 15.0 to 45.0 mass% of W with the remainder being Rh; and a γ' phase (Rh 3 (Al, W)) having an L1 2 structure is dispersed as an essential strengthening phase in a matrix, optionally the Rh alloy comprises 0.001 to 2.0 mass% in total of one or more of additive elements selected from the following Group I and 50 mass% or more of Rh as the remainder: Group I: B: 0.001 to 1.0 %, C: 0.001 to 1.0 %, Mg: 0.001 to 0.5 %, Ca: 0.001 to 1.0 %, Y: 0.01 to 1.0 %, La or a misch metal: 0.01 to 1.0 %, and further optionally the Rh-based alloy comprises 0.1 to 48.9 mass% in total of one or more of additive elements selected from the following Group II and 50 mass% or more of Rh as the remainder; and a γ' phase (Rh, X) 3 (Al, W, Z) having an L1 2 structure is dispersed as an essential strengthening phase in a matrix, wherein X is Co, Fe, Cr, Rh, Re, Pd, Pt and/or Ru; Z is Mo, Ti, Nb, Zr, V, Ta and/or Hf; and Ni is included in both X and Z: Group II: Ni: 0.1 to 48.9%, Co: 0.1 to 48.9%, Cr: 0.1 to 15%, Fe: 0.1 to 20%, Mo: 0.1 to 15%, Ti: 0.1 to 10%, Nb: 0.1 to 15%, Ta: 0.1 to 25%, V: 0.1 to 20%, Zr: 0.1 to 15%, Hf: 0.1 to 25 %, Ir: 0.1 to 15%, Re: 0.1 to 25%, Pd: 0.1 to 15%, Pt: 0.1 to 25%, Ru: 0.1 to 15%. Group I: B: 0.001 to 1.0 %, C: 0.001 to 1.0 %, Mg: 0.001 to 0.5 %, Ca: 0.001 to 1.0 %, Y: 0.01 to 1.0 %, La or a misch metal: 0.01 to 1.0 %, and further optionally the Rh-based alloy comprises 0.1 to 48.9 mass% in total of one or more of additive elements selected from the following Group II and 50 mass% or more of Rh as the remainder; and a γ' phase (Rh, X) 3 (Al, W, Z) having an L1 2 structure is dispersed as an essential strengthening phase in a matrix, wherein X is Co, Fe, Cr, Rh, Re, Pd, Pt and/or Ru; Z is Mo, Ti, Nb, Zr, V, Ta and/or Hf; and Ni is included in both X and Z: B: 0.001 to 1.0 %, C: 0.001 to 1.0 %, Mg: 0.001 to 0.5 %, Ca: 0.001 to 1.0 %, Y: 0.01 to 1.0 %, La or a misch metal: 0.01 to 1.0 %, and further optionally the Rh-based alloy comprises 0.1 to 48.9 mass% in total of one or more of additive elements selected from the following Group II and 50 mass% or more of Rh as the remainder; and a γ' phase (Rh, X) 3 (Al, W, Z) having an L1 2 structure is dispersed as an essential strengthening phase in a matrix, wherein X is Co, Fe, Cr, Rh, Re, Pd, Pt and/or Ru; Z is Mo, Ti, Nb, Zr, V, Ta and/or Hf; and Ni is included in both X and Z: further optionally the Rh-based alloy comprises 0.1 to 48.9 mass% in total of one or more of additive elements selected from the following Group II and 50 mass% or more of Rh as the remainder; and a γ' phase (Rh, X) 3 (Al, W, Z) having an L1 2 structure is dispersed as an essential strengthening phase in a matrix, wherein X is Co, Fe, Cr, Rh, Re, Pd, Pt and/or Ru; Z is Mo, Ti, Nb, Zr, V, Ta and/or Hf; and Ni is included in both X and Z: Group II: Ni: 0.1 to 48.9%, Co: 0.1 to 48.9%, Cr: 0.1 to 15%, Fe: 0.1 to 20%, Mo: 0.1 to 15%, Ti: 0.1 to 10%, Nb: 0.1 to 15%, Ta: 0.1 to 25%, V: 0.1 to 20%, Zr: 0.1 to 15%, Hf: 0.1 to 25 %, Ir: 0.1 to 15%, Re: 0.1 to 25%, Pd: 0.1 to 15%, Pt: 0.1 to 25%, Ru: 0.1 to 15%. Ni: 0.1 to 48.9%, Co: 0.1 to 48.9%, Cr: 0.1 to 15%, Fe: 0.1 to 20%, Mo: 0.1 to 15%, Ti: 0.1 to 10%, Nb: 0.1 to 15%, Ta: 0.1 to 25%, V: 0.1 to 20%, Zr: 0.1 to 15%, Hf: 0.1 to 25 %, Ir: 0.1 to 15%, Re: 0.1 to 25%, Pd: 0.1 to 15%, Pt: 0.1 to 25%, Ru: 0.1 to 15%.